Reaction chambers for the decomposition of monofuels



`lune 26, 1956 D. F. WELCH ET A1.

REACTION CHAMBERS FOR THE DECOMPOSITION OF MONOFUELS Filed OCT.. 19, 1954 2 Sheets-Sheet 1 Lillllll /NVEA/ 7' S WMM f June 26, 1956 D. F. WELCH ET AL REACTION CHAMBERS FOR THE DECOMPOSITION OF MONOFUELS 2 Sheets-Sheet 2 Filed OCt. 19, 1954 KENNETH AAR//vara/v 1PM/001.1

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197' TGP/VE Y nited States Patent *i REACTION CHAlVIBERS FOR THE DECOR/[Pl SITION 0F MONOFUELS Douglas Francis Welch, Thnrlaston, near Rugby, Kenneth Barrington Randall, Coventry, and Ian Gourlay Strang, Rugby, England, assignors to The British Thomson-Houston Company Limited, a British company Application october 19, 1954, serial No. 463,298

Claims priority, application Great Britain October 22, 1953 7 Claims. (Cl. oli-39.46)

This invention relates to apparatus for generating a ow of gaseous working fluid to produce a high energy output for a short period. The working iiuid may, for example, be supplied to a turbostarter for a prime mover, of which a gas turbine is an example.

There has previously been disclosed in the specification of patent application Serial No. 291,618, assigned to the same assignee as the present application, apparatus for generating a ow of gaseous working fluid from a liquid monofuel, i. e. a fuel which does not require an external supply of oxygen for its decomposition. In the apparatus therein described a substantially closed auxiliary reaction chamber, to which the monofuel is supplied, was provided with heating means which served to initiate decomposition of the monofuel supply to the chamber, the re sulting flow of hot gaseous fluid being led to a main reaction chamber and there used to initiate the decomposition of monofuel supplied to the main chamber, the resulting flow of gaseous fluid from the main chamber serving as the working uid.

lt is an object of the present invention to produce conditions within a main reaction chamber such that initial decomposition of the fuel supplied thereto occurs at a lower pressure than heretofore. It is a further object to provide an apparatus in which the ratio of the area of the exhaust nozzle connected with an outlet conduit from the main reaction chamber to that of the exhaust nozzle between the auxiliary and main reaction chambers to be increased, resulting in an improved overall utility factor.

lt has been the practice, heretofore, in apparatus of the kind set forth above, as shown in the specication of copending patent application Serial No. 407,123, assigned to the same assignee as the present application, to admit a separate fuel supply to the main reaction chamber through an atomizing nozzle which produces a spray of fuel in the main reaction chamber.

It is another object of the present invention to provide an arrangement in which the necessity for the use of an atomizing nozzle is removed.

According to a feature of the present invention the ow of gaseous fluid from the auxiliary reaction chamber is so directed upon admission to a main reaction chamber as to impinge substantially directly upon a jet of fuel injected through an oriiice into the said main reaction chamber thereby to elect atomization and decomposition of the jet of fuel.

According to a further feature of the present invention, in order to assist in decomposition of the monofuel supplied to the main reaction chamber, that chamber is divided into two compartments by means of a foraminous screen, one compartment containing the outlet conduit leading to a utilization device and the other compartment receiving decomposed fuel from an auxiliary reaction chamber and containing the orifice through which a separate supply of fuel is admitted to be decomposed, the foraminous screen being so disposed within the main 2,751,756 Patented June 26, 1956 ice reaction chamber as to become heated by the decomposed fuel from the auxiliary reaction chamber and to permit the separate supply of fuel to impinge upon the heated foraminous screen and thereby promote its decomposition.

The invention will be better understood from the reference to the following description of the accompanying drawings, in which Fig. l is an elevation partly in cross section of apparatus for producing a ow of gaseous working fluid in accordance with the invention; Fig. 2 is an end View taken from the left of Fig. l with a part of the apparatus removed, and Fig. 3 is an end View of Fig. l taken from the right, and Fig. 4 is a detail of a section of the apparatus on the line A-A of Fig. 2.

Referring to the drawings, the apparatus comprises an auxiliary reaction chamber 10 and a main reaction chamber 11. The main reaction chamber 11 comprises an outer casing` 12 providing a flange 13 into which the body of the auxiliary reaction chamber 10 is spigotted. The main reaction chamber is also provided with extensions having flanges 14 and 14 formed integrally therewith through which anges pass two branches 15 of an outlet conduit leading from the interior of the main reaction chamber 11. The main reaction chamber is also provided with an orifice 16 through which the monofuel to be decomposed in the main reaction chamber is led from a source of supply, not shown, by way of a supply pipe 17.

The auxiliary reaction chamber 10 is made in two parts, a main casing 1S which forms the base of the auxiliary reaction chamber and is, as above-mentioned, spigotted into the flange 13 of the main reaction chamber, and a cover member 19 which is held on to the main casing 1S by bolts 20 which pass into the flange 13 on the main reaction chamber and serve to hold the auxiliary reaction chamber in position thereon.

The cover 19 of the auxiliary reaction chamber is provided with seating 21 in which is located a jet 22 through which monofuel to be decomposed in the auxiliary reaction chamber 10 is led from a source of supply through an inlet passage 23. The auxiliary reaction chamber is also provided with heating means constituted by an electric heater element 24 in the form of a wire spiral through which heating current is passed by way of terminals 25 and 26, the heating element being bedded upon a ceramic base 27. The base 27 is held within a metal disc 28, the rim of which is flanged and spun over the edge of the ceramic base 27, the metal disc being held on the base of the auxiliary reaction chamber 10 by means of a retaining screw 29, a washer 30 and a ceramic distance piece 31, which is held on the centre of a clamping bushing 32.

The interior of the auxiliary reaction chamber 10 is connected with the interior of the main reaction chamber 11 through an exhaust nozzle 33 and transfer conduit 34, the end of which in the auxiliary reaction chamber is located between the terminals 25 and 26, the nozzle 33 being covered by a slotted bai-fie 35, shown more clearly in the detail View of Fig. 4. The other end of transfer conduit 34 within the main reaction chamber is located opposite the orifice 16 so that gaseous products of decomposition of monofuel originating in the auxiliary reaction chamber 10 are directed towards the orifice 16.

The main reaction chamber 11 is divided into two compartments by way of a foraminous screen 37. This may consist of a plurality of layers of metal gauze held within a spider 38, the outer arms of which are located within an annular support ring 39 secured to the base of the main reaction chamber 11. The spider is arranged to carry a central hollow bush 40 which forms a support for the end of transfer conduit 34.

The operation of the apparatus is initiated by supplyoriiice 16 by way of supply pipe i7. During this period the hot gas permeates the foraminous screen 37, raising its temperature so that when the separate supply of fuel Y through orice i6 is initiated, the stream of fuel is broken up'into droplets by the hotgas emerging from conduit 34 and the small droplets of fuel intermingle lwith the gas from the transfer conduit 3,4. As the intcrmznglcu fuel droplets and hot gas pass through the heated screen,

decomposition of the fuel 'is encouraged by the presen-cc of the high temperature screen and by the increased path provided by the interstices in the screen. Under these conditions decomposition of the monofuel introduced through the orifice 16 occurs at a lower pressure than heretofore. We have found that a suitable screen may be composed of 8 layers of 16 mesh 26 SFG stainless steel sauze- V By reason of the decompositionV of fuel through orifice 16 taking place at a lower pressure than heretofore, we may either maintain the same mass iow of gas from the Vmain reaction chamber 11 with a smaller area of exhaust nozzle 33, Vor alternatively, the area of the exhaust nozzle 33'from the auxiliary reaction chamber may be increased and the mass iiow from the main reaction chamber increased by increasing the area of the nozzles ted by outlet conduit 15. Y Y

Although a specific embodiment of the invention hasV been described in the foregoing specification, it is to be understood that various changes may be made in the construction illustrated without departing from the scope of the invention. For example, the transfer conduit 34 need not terminate opposite the orice 16 when the screen is employed; nor need the orifice 16 be located in the precise position illustrated provided it is on the side of the screen opposite to'that at'which the outletconduit is located; these modications are within the scope of the invention as set forth in the appended claims.

What we clair-n as new and desire to secure by Letters Patent of the United States is:

1 Apparatus for producing a flow of gaseous working iluid comprising a main reaction chamber, lorifice means for introducing a jet of monofuel into said reaction charnber, an auxiliary reaction chamber, heating means in said auxiliary reaction chamber, means for introducing atomized monofuel into said auxiliary reaction chamber so that said atomized monofuel impinges onsaid heating means, a transfer conduit leading from said auxiliary reaction chamber into said main reaction chamber, said transfer conduit being directed so that decomposed monofuel from said auxiliary reaction chamber impingcs Vdirectly upon said orice'means, and an outlet conduit leading from said main reaction chamber for conveying the ow of gaseous working fluid produced byY decomposition of monofuel introduced through said orifice means. f Y Y 2. Apparatus for producing a ow of gaseous working fluid comprising a main reaction chamber, orifice means for introducing a ,iet monofuel into said reaction charnber, an auxiliary reaction chamber, heating means in said auxiliary reaction chamber, means for so introducing atomized monofuel into said auxiliary reaction chamber that it impinges on Ysaid heating means, a foraminous screen dividing said main reaction chamber into two contpartments in one of which said orifice means is located, an outlet conduit leading from the other of said compartments, a transfer conduit leading from said auxiliary rcaction chamber into said one of said compartments for Vcausing decomposed monofuel originating in said auxiliary reaction chamber to enter said one compartment and pass through the apertures in said screen whereby to heat said screen and encourage vaporization decomposition of monofuel introduced through said orifice means, thereby to produce through said outlet conduit the iiow of gaseous working iiuid resulting from the decomposition of monofuel introduced through said orice means.

3. Apparatus for producing a iiow of gaseous working fluid as claimed in claim 2 in which the said'transfcr conduit leads through said foraminous screen and terminates opposite said orifice means whereby the ow of hot gasV- eous fluid from said auxiliary reaction chamber utilized to encourage vapori/.ation of monofuel introduced into said main reaction chamber through said orih'ce means.

4. Apparatus for producing a ilow of gaseous workingV uid as claimed in claim 2, in which said foraminous screen is composed of layers of metal gauze with the apertures in succeeding iayers substaniialiy in misaiigament whereby to provide circuitous paths for the passage of gaseous uid through said screen. Y

5. Apparatus for producing a how of gaseous working fluid as claimed in claim 2, in which the area of a nozzle through which heated gaseous fluid passes from said auxiliary reaction chamber into said main reaction chamber is less than the area of a nozzle in said outlet conduit in order to build up pressure within said main reaction chamber. Y

6. Apparatus for producing a ow of gaseous working fluid as claimed in claim 2, in which said heating means is constituted by an'relcctricallyfheated conductor.

7. Apparatus for producing a ilow of gaseous working iluid as claimed in claim 2 in which said auxiliary reaction chamber is directly mountedV on said main reaction chamber.

2,574,495 Parker Nov. 13, 1951 

1. APPARATUS FOR PRODUCING A FLOW OF GASEOUS WORKING FLUID COMPRISING A MAIN REACTION CHAMBER, ORIFICE MEANS FOR INTRODUCING A JET OF MONOFUEL INTO SAID REACTION CHAMBER, AND AUXILIARY REACTION CHAMBER, HEATING MEANS IN SAID AUXILIARY REACTION CHAMBER, MEANS FOR INTRODUCING ATOMLIZED MONOFUEL INTO SAID AUXILIARY REACTION CHAMBER SO THAT SAID ATOMIZED MONOFUEL IMPINGES ON SAID HEATING MEANS, A TRANSFER CONDUIT LEADING FROM SAID AUXILIARY REACTION CHAMBER INTO SAID MAIN REACTION CHAMBER, SAID TRANSFER CONDUIT BEING DIRECTED SO THAT DECOMPOSED MONOFUEL FROM SAID AUXILIARY REACTION CHAMBER IMPINGES DIRECTLY UPON SAID ORIFICE MEANS, AND AN OUTLET CONDUIT LEADING FROM SAID MAIN REACTION CHAMBER FOR CONVEYING THE FLOW OF GASEOUS WORKING FLUID PRODUCED BY DECOMPOSITION OF MONOFUEL INTRODUCED THROUGH SAID ORIFICE MEANS. 